1. Field
A reciprocating compressor is disclosed herein.
2. Background
In general, a reciprocating compressor employs a method of inhaling, compressing, and discharging refrigerant while a piston performs a reciprocating movement at high speed within a cylinder. The reciprocating compressor may be divided into a connection type and a vibration type according to a driving method of its piston.
A connection type reciprocating compressor employs a method in which a piston is connected to a rotation shaft of a rotation motor to compress refrigerant while performing a reciprocating movement within a cylinder. In contrast, a vibration type reciprocating compressor employs a method in which a piston is connected to a mover of a reciprocating motor to compress refrigerant while performing a reciprocating movement using vibration within a cylinder. Embodiments disclosed herein relate to a vibration type reciprocating compressor, and hereinafter, the vibration type reciprocating compressor will be referred to as a reciprocating compressor.
FIG. 1 is a cross-sectional view of a related art reciprocating compressor. As illustrated in FIG. 1, in a reciprocating compressor according to the related art, a frame 20 may be elastically supported by a plurality of support springs 61, 62 at an inner space 10a of an enclosed shell 10, and an outer stator 31 and an inner stator 32 of a reciprocating motor 30 forming a motor (M) and a cylinder 41 forming a compressor device (C), which will be described later, may be provided on the frame 20. The cylinder 41 may be provided within a range of being overlapped with the stators 31, 32 of the reciprocating motor 30 in an axial direction.
A piston 42 coupled to a mover 33 of the reciprocating motor 30 to form the compressor device (C) along with the cylinder 41 may be inserted into and coupled to the cylinder 41 to perform a reciprocating movement, and a plurality of resonant springs 51, 52 to include a resonant movement of the piston 42 may be provided at both sides of a movement direction of the piston 42, respectively.
Further, a suction pipe 11 connected to an evaporator (not shown) of a refrigeration cycle apparatus may be provided to communicate with the inner space 10a of the shell 10, and a discharge pipe 12 connected to a condenser (not shown) of the refrigeration cycle apparatus may be provided to communicate with one side of the suction pipe 11.
Furthermore, a compression space (S1) may be formed in the cylinder 41, a suction passage (F) to guide refrigerant to the compression space (S1) may be formed on the piston 42, a suction valve 43 to open and close the suction passage (F) may be provided at an end of the suction passage (F), and a discharge valve 44 to open and close the compression space (S1) of the cylinder 41 may be provided at a leading end surface of the cylinder 41.
Unexplained reference numerals 35, 36 and 45 in FIG. 1 denote a coil, a magnet, and a valve spring, respectively.
According to the above-described related art reciprocating compressor, when power is applied to the coil 35 of the reciprocating motor 30, the mover 33 of the reciprocating motor 30 may perform a reciprocating movement. Then, the piston 42 coupled to the mover 33 may inhale refrigerant into the inner space 10a of the piston 42 through the suction pipe 11 while performing a reciprocating movement at high speed within the cylinder 41 at the inner space 10a of the shell 10. Then, refrigerant at the inner space 10a of the shell 10 may be inhaled into the compression space (S1) of the cylinder 41 through the suction passage (F) of the piston 42, and discharged from the compression space (S1) during a forward movement of the piston 42, thereby repeating a series of processes of moving refrigerant to the condenser of the refrigeration cycle apparatus through the discharge pipe 12.
However, according to the above-described related art reciprocating compressor, the compressor device (C) may be provided in an overlapping manner at an inner side of the motor (M), and therefore, a magnetic flux generated by the motor (M) may be leaked to the compressor device (C) along the frame 20, increasing motor loss, and the reciprocating movement of the piston 42 may be destabilized by the magnetic flux leaked to the compressor device (C). If the cylinder 41 and piston 42 are formed of a non-magnetic material to prevent the magnetic flux of the motor (M) from being leaked to the compressor device (C), it may cause a problem of increasing production costs and reducing reliability of the compressor due to low abrasion resistance.
In addition, according to the above-described related art reciprocating compressor, the mover 33 may be inserted between the stators 31, 32, and the piston 42 may be inserted into the cylinder 41, in a state in which the piston 42 is coupled to the mover 33 and the outer stator 31 and inner stator 32 are assembled together, to align the concentricity of the mover 33 and piston 42. Due to this, mismatch may frequently occur in which the concentricity of the motor (M) and compressor device (C) deviate, thereby deteriorating compressor performance while causing leakage of refrigerant as abrasion between the cylinder 41 and piston 42 is increased or a gap between the cylinder 41 and piston 42 is partially out of a permissible range.